Visible Kerr comb generation in a high-Q silica microdisk resonator with a large wedge angle

This paper describes the specially designed geometry of a dry-etched large-wedge-angle silica microdisk resonator that enables anomalous dispersion in the 780 nm wavelength regime. This anomalous dispersion occurs naturally without the use of a mode-hybridization technique to control the geometrical dispersion. By fabricating a 1-mu m-thick silica microdisk with a wedge angle as large as 56 degrees and an optical Q-factor larger than 10(7), we achieve a visible Kerr comb that covers the wavelength interval of 700-897 nm. The wide optical frequency range and the closeness to the clock transition at 698 nm of Sr-87 atoms make our visible comb a potentially useful tool in optical atomic clock applications. (c) 2019 Chinese Laser Press.